add KSpace style zero to KSPACE and zero2 as plugin demo

examples/plugins/CMakeLists.txt

@@ -94,6 +94,10 @@ add_library(zero2plugin MODULE zero2plugin.cpp pair_zero2.cpp bond_zero2.cpp
                                angle_zero2.cpp dihedral_zero2.cpp improper_zero2.cpp)
 target_link_libraries(zero2plugin PRIVATE lammps)
 
+add_library(kspaceplugin MODULE kspaceplugin.cpp kspace_zero2.cpp)
+target_include_directories(kspaceplugin PRIVATE "${LAMMPS_HEADER_DIR}/KSPACE")
+target_link_libraries(kspaceplugin PRIVATE lammps)
+
 set_target_properties(morse2plugin nve2plugin helloplugin zero2plugin PROPERTIES PREFIX "" SUFFIX ".so")
 
 # MacOS seems to need this

examples/plugins/kspace_zero2.cpp

@@ -0,0 +1,117 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/, Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+/* ----------------------------------------------------------------------
+   Contributing author: Axel Kohlmeyer (Temple U)
+------------------------------------------------------------------------- */
+
+#include "kspace_zero2.h"
+
+#include "atom.h"
+#include "comm.h"
+#include "domain.h"
+#include "error.h"
+#include "force.h"
+#include "pair.h"
+
+#include <cstring>
+
+using namespace LAMMPS_NS;
+
+/* ---------------------------------------------------------------------- */
+
+KSpaceZero2::KSpaceZero2(LAMMPS *lmp) : KSpace(lmp)
+{
+  ewaldflag = 1;
+  pppmflag = 1;
+  msmflag = 1;
+  dispersionflag = 1;
+  tip4pflag = 1;
+  dipoleflag = 1;
+  spinflag = 1;
+}
+
+KSpaceZero2::~KSpaceZero2()
+{
+  fprintf(stderr, "In destructor for KSpace zero2. This = %p\n", this);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero2::settings(int narg, char **arg)
+{
+  if (narg != 1) error->all(FLERR, "Illegal kspace_style {} command", force->kspace_style);
+
+  accuracy_relative = fabs(utils::numeric(FLERR, arg[0], false, lmp));
+  if (accuracy_relative > 1.0)
+    error->all(FLERR, "Invalid relative accuracy {:g} for kspace_style {}", accuracy_relative,
+               force->kspace_style);
+  if ((narg != 0) && (narg != 1)) error->all(FLERR, "Illegal kspace_style command");
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero2::init()
+{
+  if (comm->me == 0) utils::logmesg(lmp, "Dummy KSpace initialization ...\n");
+
+  // error checks
+
+  if (force->pair == nullptr) error->all(FLERR, "KSpace solver requires a pair style");
+  if (!atom->q_flag) error->all(FLERR, "KSpace style zero2 requires atom attribute q");
+
+  // compute two charge force
+
+  two_charge();
+
+  int itmp;
+  auto p_cutoff = (double *) force->pair->extract("cut_coul", itmp);
+  if (p_cutoff == nullptr) error->all(FLERR, "KSpace style is incompatible with Pair style");
+  double cutoff = *p_cutoff;
+
+  qsum_qsq();
+
+  accuracy = accuracy_relative * two_charge_force;
+
+  // make initial g_ewald estimate
+  // based on desired accuracy and real space cutoff
+  // fluid-occupied volume used to estimate real-space error
+  // zprd used rather than zprd_slab
+
+  if (!gewaldflag) {
+    if (accuracy <= 0.0) error->all(FLERR, "KSpace accuracy must be > 0");
+    if (q2 == 0.0) error->all(FLERR, "Must use 'kspace_modify gewald' for uncharged system");
+    g_ewald = accuracy * sqrt(atom->natoms * cutoff * domain->xprd * domain->yprd * domain->zprd) /
+        (2.0 * q2);
+    if (g_ewald >= 1.0)
+      g_ewald = (1.35 - 0.15 * log(accuracy)) / cutoff;
+    else
+      g_ewald = sqrt(-log(g_ewald)) / cutoff;
+  }
+
+  if (comm->me == 0) std::string mesg = fmt::format("  G vector (1/distance) = {:.8g}\n", g_ewald);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero2::setup()
+{
+  if (comm->me == 0) utils::logmesg(lmp, "Dummy KSpace setup\n");
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero2::compute(int eflag, int vflag)
+{
+  ev_init(eflag, vflag);
+}

examples/plugins/kspace_zero2.h

@@ -0,0 +1,33 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/ Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifndef LMP_KSPACE_ZERO2_H
+#define LMP_KSPACE_ZERO2_H
+
+#include "kspace.h"
+
+namespace LAMMPS_NS {
+
+class KSpaceZero2 : public KSpace {
+ public:
+  KSpaceZero2(class LAMMPS *);
+  ~KSpaceZero2() override;
+
+  void init() override;
+  void setup() override;
+  void settings(int, char **) override;
+
+  void compute(int, int) override;
+};
+}    // namespace LAMMPS_NS
+#endif

examples/plugins/kspaceplugin.cpp

@@ -0,0 +1,35 @@
+
+#include "lammpsplugin.h"
+
+#include "comm.h"
+#include "command.h"
+#include "error.h"
+#include "version.h"
+
+#include <cstring>
+
+#include "kspace_zero2.h"
+
+using namespace LAMMPS_NS;
+
+static KSpace *zero2creator(LAMMPS *lmp)
+{
+  KSpace *ptr = (KSpace *) new KSpaceZero2(lmp);
+  fprintf(stderr, "Created zero2 instance at %p\n", ptr);
+  return ptr;
+}
+
+extern "C" void lammpsplugin_init(void *lmp, void *handle, void *regfunc)
+{
+  lammpsplugin_t plugin;
+  lammpsplugin_regfunc register_plugin = (lammpsplugin_regfunc) regfunc;
+
+  plugin.version = LAMMPS_VERSION;
+  plugin.style = "kspace";
+  plugin.name = "zero2";
+  plugin.info = "zero2 KSpace style v1.0";
+  plugin.author = "Axel Kohlmeyer (akohlmey@gmail.com)";
+  plugin.creator.v1 = (lammpsplugin_factory1 *) &zero2creator;
+  plugin.handle = handle;
+  (*register_plugin)(&plugin, lmp);
+}

src/KSPACE/kspace_zero.cpp

@@ -0,0 +1,117 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/, Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+/* ----------------------------------------------------------------------
+   Contributing author: Axel Kohlmeyer (Temple U)
+------------------------------------------------------------------------- */
+
+#include "kspace_zero.h"
+
+#include "atom.h"
+#include "comm.h"
+#include "domain.h"
+#include "error.h"
+#include "force.h"
+#include "pair.h"
+
+#include <cstring>
+
+using namespace LAMMPS_NS;
+
+/* ---------------------------------------------------------------------- */
+
+KSpaceZero::KSpaceZero(LAMMPS *lmp) : KSpace(lmp)
+{
+  ewaldflag = 1;
+  pppmflag = 1;
+  msmflag = 1;
+  dispersionflag = 1;
+  tip4pflag = 1;
+  dipoleflag = 1;
+  spinflag = 1;
+}
+
+KSpaceZero::~KSpaceZero()
+{
+  fprintf(stderr, "In destructor for KSpace zero. This = %p\n", this);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero::settings(int narg, char **arg)
+{
+  if (narg != 1) error->all(FLERR, "Illegal kspace_style {} command", force->kspace_style);
+
+  accuracy_relative = fabs(utils::numeric(FLERR, arg[0], false, lmp));
+  if (accuracy_relative > 1.0)
+    error->all(FLERR, "Invalid relative accuracy {:g} for kspace_style {}", accuracy_relative,
+               force->kspace_style);
+  if ((narg != 0) && (narg != 1)) error->all(FLERR, "Illegal kspace_style command");
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero::init()
+{
+  if (comm->me == 0) utils::logmesg(lmp, "Dummy KSpace initialization ...\n");
+
+  // error checks
+
+  if (force->pair == nullptr) error->all(FLERR, "KSpace solver requires a pair style");
+  if (!atom->q_flag) error->all(FLERR, "KSpace style zero requires atom attribute q");
+
+  // compute two charge force
+
+  two_charge();
+
+  int itmp;
+  auto p_cutoff = (double *) force->pair->extract("cut_coul", itmp);
+  if (p_cutoff == nullptr) error->all(FLERR, "KSpace style is incompatible with Pair style");
+  double cutoff = *p_cutoff;
+
+  qsum_qsq();
+
+  accuracy = accuracy_relative * two_charge_force;
+
+  // make initial g_ewald estimate
+  // based on desired accuracy and real space cutoff
+  // fluid-occupied volume used to estimate real-space error
+  // zprd used rather than zprd_slab
+
+  if (!gewaldflag) {
+    if (accuracy <= 0.0) error->all(FLERR, "KSpace accuracy must be > 0");
+    if (q2 == 0.0) error->all(FLERR, "Must use 'kspace_modify gewald' for uncharged system");
+    g_ewald = accuracy * sqrt(atom->natoms * cutoff * domain->xprd * domain->yprd * domain->zprd) /
+        (2.0 * q2);
+    if (g_ewald >= 1.0)
+      g_ewald = (1.35 - 0.15 * log(accuracy)) / cutoff;
+    else
+      g_ewald = sqrt(-log(g_ewald)) / cutoff;
+  }
+
+  if (comm->me == 0) std::string mesg = fmt::format("  G vector (1/distance) = {:.8g}\n", g_ewald);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero::setup()
+{
+  if (comm->me == 0) utils::logmesg(lmp, "Dummy KSpace setup\n");
+}
+
+/* ---------------------------------------------------------------------- */
+
+void KSpaceZero::compute(int eflag, int vflag)
+{
+  ev_init(eflag, vflag);
+}

src/KSPACE/kspace_zero.h

@@ -0,0 +1,40 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/ Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifdef KSPACE_CLASS
+// clang-format off
+KSpaceStyle(zero,KSpaceZero);
+// clang-format on
+#else
+
+#ifndef LMP_KSPACE_ZERO_H
+#define LMP_KSPACE_ZERO_H
+
+#include "kspace.h"
+
+namespace LAMMPS_NS {
+
+class KSpaceZero : public KSpace {
+ public:
+  KSpaceZero(class LAMMPS *);
+  ~KSpaceZero() override;
+
+  void init() override;
+  void setup() override;
+  void settings(int, char **) override;
+
+  void compute(int, int) override;
+};
+}    // namespace LAMMPS_NS
+#endif
+#endif